US4529929A - Method of detecting ground faults in a network for distribution of electric power and a device for carrying out the method - Google Patents

Method of detecting ground faults in a network for distribution of electric power and a device for carrying out the method Download PDF

Info

Publication number
US4529929A
US4529929A US06/437,634 US43763482A US4529929A US 4529929 A US4529929 A US 4529929A US 43763482 A US43763482 A US 43763482A US 4529929 A US4529929 A US 4529929A
Authority
US
United States
Prior art keywords
ground fault
fault current
line
measured
value
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US06/437,634
Other languages
English (en)
Inventor
Jan Berggren
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ABB Norden Holding AB
Original Assignee
ASEA AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ASEA AB filed Critical ASEA AB
Assigned to ASEA AKTIEBOLAG VASTERAS,SWEDEN A SWEDISH CORP. reassignment ASEA AKTIEBOLAG VASTERAS,SWEDEN A SWEDISH CORP. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: BERGGREN, JAN
Application granted granted Critical
Publication of US4529929A publication Critical patent/US4529929A/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/08—Locating faults in cables, transmission lines, or networks
    • G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
    • G01R31/086—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
    • G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
    • G01R27/16—Measuring impedance of element or network through which a current is passing from another source, e.g. cable, power line
    • G01R27/18—Measuring resistance to earth, i.e. line to ground
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/16—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to fault current to earth, frame or mass
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S10/00—Systems supporting electrical power generation, transmission or distribution
    • Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
    • Y04S10/52—Outage or fault management, e.g. fault detection or location

Definitions

  • the present invention relates to a method of detecting ground faults in a network for distribution of electric power from a power station, from which a number of lines, included in the network, emanate, and to a device for carrying out this method.
  • Radially supplied distribution networks have to be protected against ground faults in such a way that a component or a line, on which a fault has occurred, is automatically disconnected by means of its circuit-breaker. This is necessary in order to minimize the risk of personal injury and fires.
  • the embodiment of a ground fault protection device is substantially determined by the size of the network, its grounding and the regulations which apply to electric heavy current installations as regards permissible voltages in case of a ground fault on a grounded component. Because of the different appearances of the networks, several different types of measurement criteria are therefore used at the present.
  • X C the capacitive reactance of the network to ground ( ⁇ /phase)
  • R 0 the inner resistance of the neutral point reactor ( ⁇ )
  • I J the ground fault current of the network (A)
  • I JR the component of the ground fault current which is in phase with the neutral point voltage U o (A)
  • I JR the peak value of I JR (A)
  • ⁇ I J the alteration of the ground fault current of the network (A)
  • R F transition resistance to ground at the site of the fault ( ⁇ )
  • detection of ground faults is carried out in several ways, among other things depending on if and how the network is grounded.
  • directional overcurrent relays are used, which are sensitive to ground fault currents which are capacitive relative to the neutral point voltage.
  • Grounding via a neutral point resistor where R N is greater than 50 ⁇ occurs in small and medium-sized networks.
  • the neutral point resistor R N is selected so that sufficient active, or as it is also called, resistive current, i.e. current which is in phase with the neutral point voltage, is obtained in case of a ground fault.
  • resistive current i.e. current which is in phase with the neutral point voltage
  • the network is protected by directional overcurrent relays which are sensitive to resistive ground fault current and which are fed with the current which passes via the neutral point resistor.
  • Grounding by means of a neutral point reactor X N and a neutral point resistor R N occurs in large-sized networks where the capacitive ground fault current would otherwise become too high.
  • the capacitive ground fault current is compensated with the neutral point reactor in such a way that a tuned network is obtained.
  • directional overcurrent relays which are sensitive to resistive ground fault current, i.e. the current through the neutral point resistor.
  • resistive ground fault current i.e. the current through the neutral point resistor.
  • there may be provided a special automatic system which handles the disconnection and connection of the neutral point resistor, so that a chance of self-extinction of the fault is given, before a relay starts functioning and disconnects the line.
  • Grounding with a neutral point reactor X N occurs in very large networks. Otherwise, the same applies as when grounding with a reactor and a resistor; however, it is assumed that the inner resistance R 0 of the neutral point reactor shall be sufficiently high to permit evaluation of a resistive current component.
  • Ungrounded networks also give relatively good possibilities of selective detection of ground faults with high transition resistance. However, ungrounded networks are less common since only small networks can then be used. Furthermore, it is normally desired to avoid ungrounded networks in view of the risk of intermittent ground faults.
  • the angular fault of the current transformer may cause incorrect measurement.
  • ground faults which cannot be located and disconnected in time may lead to personal injury or to fire.
  • so-called reversed ground faults should be of special interest, i.e. faults where a phase has an interruption and a ground fault occurs in the phase after the place of the interruption with power supply via the load object. In the present situation, these faults may remain undiscovered for a long period of time.
  • the demand for current transformers can be considered moderate in view of the fact that systematic deviations are compensated away.
  • the system can easily be supplemented with an automatic system for reclosing and a neutral point automatic system without any major costs.
  • the ground fault current (I J ) for each line is measured and the line, which shows the greatest resistive ground fault current (I JR ), or the greatest ground fault current (I J ), or the greatest change in the ground fault current ( ⁇ I J ), is selected, whereafter the measured resistive ground fault current (I JR ), or ground fault current (I J ), or change thereof in the selected line is compared with at least one predetermined reference value and a fault indication is obtained at a level exceeding said reference value.
  • the resistive ground fault current for all lines is measured instantaneously when the rate of change of the neutral point voltage changes signs, i.e. I JR is measured, whereafter the measured values are added for each line, so that the sum becomes a measure of the amount of the active component of the ground fault current.
  • the ground fault current (I J ) can be measured instantaneously for all the lines on a plurality of measurement occasions during each cycle of power frequency and a specified number of the measured values be summed up for each line back in time in order to thus form a measure of the amount of said ground fault current.
  • the difference between measured value on one measuring occasion and measured value on a corresponding measuring occasion during the preceding period is continuously formed.
  • the sum of the amounts of the individual differences--obtained for each measuring occasion--in ground fault current during two periods of power frequency is formed, from where the change in ground fault current ( ⁇ I J ) is created.
  • the measurement of the ground fault current (I JR ) is initiated and proceeds for as long as the neutral point voltage (U 0 ) of the network reaches a certain predetermined value.
  • members for measuring the ground fault current (I J ) for each line members for selecting the line which shows the greatest active ground fault current (I JR ), the greatest ground fault current (I J ), or the greatest change in ground fault current, members for comparing measured resistive ground fault current (I JR ), or measured ground fault current (I J ), or the change thereof, with at least one predetermined reference value, and members for delivering a fault-indicating output signal at a level exceeding the reference value.
  • the above-mentioned members comprise an interface unit, arranged for each line and arranged to receive at its input the ground fault current (I J ) of the respective line, and a measuring unit for the ground fault current connected after the interface units, said measuring unit having an output arranged for each line, said outputs being arranged to deliver fault indicating output signals.
  • Said members also comprise a measuring unit for neutral point voltage (U 0 ) arranged to receive neutral point voltage at its input and to deliver an output signal at its output, said output signal--if the amplitude reaches a predetermined value--giving information about the time when the rate of change of the neutral point voltage changes sign.
  • U 0 neutral point voltage
  • Said measuring unit for ground fault current (I J ) is arranged to measure both the change in ground fault current ( ⁇ I J ) and the absolute value of the ground fault current or its active component and, at a value exceeding a predetermined reference value, to deliver a fault indicating output signal.
  • the object of the invention is to measure and mutually compare the ground fault current (I J ) of all the lines. The greatest of the currents is compared with a set reference.
  • measuring method 1 measures the instantaneous value of the current twice every power frequency cycle at a time corresponding, in phase, to 90° after the zero passage of the neutral point voltage, i.e. the peak value of the resistive ground fault current component is measured. This method consequently requires a neutral point resistor but is otherwise independent of the embodiment of the network.
  • the instantaneous value is measured at times which are controlled by an interval clock.
  • this method requires no measurement of the neutral point voltage U 0 as the synchronization to power frequency takes place by means of the interval clock. Nor does this method place any demands on the neutral point resistor, whether it exists or not.
  • FIG. 1 shows the case where only the peak value of the ground fault current component which is in phase with the neutral point voltage is utilized.
  • Block No. 2 designates a multiplexed A/D convertor.
  • Blocks Nos. 7 and 13 designate a demultiplexer.
  • Block No. 10 designates a maximum value detector, i.e. an element which scans a number of incoming signals and finds out which is the greatest. The maximum value detector has two outputs, one indicating the maximum value and the other indicating which of the incoming lines has the maximum value.
  • FIG. 2 shows an embodiment which monitors both the ground fault current as such and the change in the ground fault current and allows the currents which first reaches a reference value, set in advance for each of the currents, to cause a tripping signal.
  • the ground fault currents of all lines which normally are practically zero, are available in the form of the signals I J1 , I J2 and so on.
  • the measured current passes through an interface unit (1) in which the current signal is transformed into a suitable voltage and in which also filtering takes place.
  • Each line has its own interface unit.
  • the output from the interface units is arranged to be connected to a multiplexed A/D convertor (2).
  • the device comprises a measuring unit (3) for measuring the neutral point voltage. When said voltage exceeds a set reference value U 0 ref (4), the threshold element (5) is opened for passage of U 0 to the control pulse device (6) of the multiplexed A/D convertor.
  • This device (6) emits a start impulse to the multiplexed A/D convertor each time that U 0 passes a maximum. At that time, measurement of the instantaneous value of all the line currents takes place. This value corresponds to the peak value of that component of the ground fault current which is in phase with the neutral point voltage.
  • the multiplexed A/D convertor supplies a digital value for each line which corresponds to I JR . These values are supplied to a demultiplexer (7) which is controlled by the same control pulse device (6), whereupon the measured values are supplied to and stored in a memory (8) for each line. The next time the pulse device (6) delivers a start impulse, i.e.
  • the ground fault currents of all the lines are available in the form of signals I J1 , I J2 and so on.
  • the measured current passes through an interface unit (1) where the current signal is transformed into a suitable voltage and where also filtering takes place.
  • Each line has its own interface unit.
  • the output from the interface units is arranged to be connected to a multiplexed A/D convertor (2).
  • the device comprises an interval clock (3).
  • the clock (3) generates start pulses to the multiplexed A/D convertor a fixed number of times each cycle. The start pulses return with the same intermittence and the n:th pulse in a cycle recurs in the next cycle at the same phase position relative to the supplying network.
  • Each instantaneous value, measured for each line and converted into a digital value, is supplied partly directly to a demultiplexer (4), partly via a time delay (5) of one cycle to another demultiplexer (6).
  • the demultiplexers (4) and (6) are controlled by the interval clock (3) with the same start pulses as the multiplexed A/D convertor (2).
  • the difference between the instantaneous value of each line and the corresponding value one cycle previously for each measuring occasion is obtained by means of the difference generators (7), (8) and corresponding difference generators for the other lines.
  • the values conveyed by the demultiplexer (4) are supplied to a memory (9). Each time that the interval clock (3) delivers a start pulse, a new measured value is added for each line.
  • a summation of the measured values for each cycle is obtained by the summators (10).
  • the value received for each cycle represents a measure of the ground fault current during this cycle.
  • An updating of the memory takes place for each cycle.
  • the same procedure is repeated for the values which represent the change currents, i.e. the output signals from the difference generators (7), (8), etc., which are supplied to a memory (11) and are processed in a summator (12).
  • the only difference is that a change of the ground fault current ⁇ I J is formed as the sum of the amounts of the individual differences--obtained for each measuring occasion--in ground fault current during two cycles of power frequency.
  • the maximum value detectors (13) and (14), which are also controlled by the interval clock (3) all the values are scanned and at the outputs there is obtained information about which line (line “i") has the greatest ground fault current I J and a value corresponding to the magnitude of the current, and about which line (line “ii") has the greatest change current ⁇ I J L and a measure of the value.
  • the current value I J MAX is compared with a reference value I J ref (15).
  • the threshold element (16) delivers a signal to the or-element (17) when I J MAX>I J ref.
  • the output of the or-element (17) is connected via a settable time delay element (18) to the and-element (19).
  • the second criterion of a tripping signal (u) being supplied is that the neutral point voltage exceeds a set reference value U 0 ref (20).
  • the threshold element (21) delivers a signal to the and-element (19) when U 0 >U 0 ref.
  • the output of the and-element (19) is connected to the demultiplexer (22) which, with the aid of the line information line " i" supplies a tripping signal (u) to a faulty line.
  • the output signals of the maximum value detector (14) are each led to a memory (23 and 24). These memories are set to zero and are continuously updated for each scanning operation in the maximum value detector.
  • the output from the memory (23) which corresponds to ⁇ I J MAX is compared with a set reference value ⁇ I J ref (25), and when ⁇ I J MAX>> ⁇ I J ref the threshold element (26) gives an output signal which is supplied as a second input signal to the or-element (17).
  • the output signal of the threshold element (26) is also supplied to a locking element (27) which, when a signal is received, blocks the memories (23 and 24) for a certain time. This arrangement is necessary to ensure that the information from the maximum value detector (14) is maintained after the time delay caused by the element (18).
  • the line information (line "i") for controlling the tripping operation to the correct line is then maintained and is supplied to the demultiplexer (22).

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
  • Emergency Protection Circuit Devices (AREA)
  • Locating Faults (AREA)
US06/437,634 1981-11-02 1982-10-29 Method of detecting ground faults in a network for distribution of electric power and a device for carrying out the method Expired - Fee Related US4529929A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE8106436A SE446678B (sv) 1981-11-02 1981-11-02 Metod att detektera jordfel i net for distribution av elektrisk kraft och anordning for genomforande av metoden
SE8106436 1981-11-02

Publications (1)

Publication Number Publication Date
US4529929A true US4529929A (en) 1985-07-16

Family

ID=20344926

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/437,634 Expired - Fee Related US4529929A (en) 1981-11-02 1982-10-29 Method of detecting ground faults in a network for distribution of electric power and a device for carrying out the method

Country Status (8)

Country Link
US (1) US4529929A (no)
EP (1) EP0082103B1 (no)
CA (1) CA1191904A (no)
DE (1) DE3270665D1 (no)
DK (1) DK484082A (no)
FI (1) FI74365C (no)
NO (1) NO157758C (no)
SE (1) SE446678B (no)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4797805A (en) * 1985-12-20 1989-01-10 Asea Aktiebolag Fault location in a power supply network
US4800374A (en) * 1986-10-31 1989-01-24 Cray Research, Inc. Personnel antistatic test device
US4800509A (en) * 1985-12-20 1989-01-24 Asea Aktiebolag Detection of high resistance faults in electrical power supply network
US4851782A (en) * 1987-01-15 1989-07-25 Jeerings Donald I High impedance fault analyzer in electric power distribution
DE4011076A1 (de) * 1989-04-05 1990-10-18 Chubu Electric Power Nullstromdetektor
US4991105A (en) * 1988-12-21 1991-02-05 Accu-Scan, Inc. Microprocessor controlled ground system monitor
DE4413068A1 (de) * 1993-04-15 1994-10-20 Hitachi Ltd Vorrichtung zum Erkennen einer Isolierungsverschlechterung
US5365179A (en) * 1992-03-19 1994-11-15 Electronic Development, Inc. Apparatus and method for measuring ground impedance
US5493228A (en) * 1993-09-28 1996-02-20 Asea Brown Boveri Ab Method and device for measuring and recreating the load current in a power network in connection with the occurrence of faults
US5506789A (en) * 1993-10-15 1996-04-09 The Texas A & M University System Load extraction fault detection system
US5550476A (en) * 1994-09-29 1996-08-27 Pacific Gas And Electric Company Fault sensor device with radio transceiver
US5790038A (en) * 1994-04-22 1998-08-04 Scasciafratti; Gianfranco System for the remote measuring of the protection ground
US5973500A (en) * 1996-06-14 1999-10-26 Electricite De France-Service National Apparatus for detecting insulation defects in devices connected into power distribution networks
WO2000062084A1 (en) * 1999-04-12 2000-10-19 Chk Wireless Technologies Australia Pty Limited Apparatus and method for electrical measurements on conductors
WO2004079378A1 (en) * 2003-03-05 2004-09-16 Jan Berggren Detection of earth faults in three phase systems
CN104237731A (zh) * 2014-09-25 2014-12-24 福州大学 基于eemd与能量法的谐振接地配电网单相接地故障选线方法
CN104597378A (zh) * 2015-01-26 2015-05-06 福州大学 基于暂态非工频零序电流的含dg配电网的故障选线方法
US9991694B1 (en) 2014-10-27 2018-06-05 Becker Mining America, Inc. Multi-channel tone monitor system and method for ground wire monitoring using same
CN111965487A (zh) * 2020-08-12 2020-11-20 国网江苏省电力有限公司盐城供电分公司 一种高压输电线路接地故障检测控制方法
US11522355B2 (en) 2018-05-18 2022-12-06 Abb Schweiz Ag Method and apparatus for use in earth-fault protection

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ATE74237T1 (de) * 1986-11-10 1992-04-15 Siemens Ag Verfahren und einrichtung zum orten eines erdschlusses eines leiters in einem drehstromnetz.
AT404072B (de) * 1995-02-28 1998-08-25 Haefely Trench Austria Gmbh Verfahren zur erkennung eines einpoligen erdschlusses in einem drehstromnetz
FI103217B (fi) * 1997-08-27 1999-05-14 Abb Transmit Oy Menetelmä sähkönjakeluverkon suuriresistanssisen maasulkuvian paikalli stamiseksi virtamittausten perusteella
ATA194698A (de) * 1998-11-20 2001-11-15 Adaptive Regelsysteme Ges M B Verfahren zur bestimmung des erdschlussbehafteten abzweiges

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3609534A (en) * 1969-05-07 1971-09-28 Gurevich Albert E Device utilizing dc transformers for selective location of earth connection within bus system
US3800215A (en) * 1971-11-19 1974-03-26 Schlumberger Compteurs Method and apparatus for localizing phase-to-phase and phase-to-ground faults in power lines
US4408155A (en) * 1981-03-02 1983-10-04 Bridges Electric, Inc. Fault detector with improved response time for electrical transmission system

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH554096A (fr) * 1970-12-17 1974-09-13 Merlin Gerin Dispositif de protection selective d'un reseau de distribution d'energie electrique.
DE2247746C3 (de) * 1972-09-29 1975-11-27 Siemens Ag, 1000 Berlin Und 8000 Muenchen Verfahren zum Messen einer Leitungsimpedanz
GB2008345B (en) * 1977-11-14 1982-08-18 Multilin Inc Method of and apparatus for monitoring polyphase currents
US4234901A (en) * 1979-03-08 1980-11-18 Westinghouse Electric Corp. Protective relay apparatus

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3609534A (en) * 1969-05-07 1971-09-28 Gurevich Albert E Device utilizing dc transformers for selective location of earth connection within bus system
US3800215A (en) * 1971-11-19 1974-03-26 Schlumberger Compteurs Method and apparatus for localizing phase-to-phase and phase-to-ground faults in power lines
US4408155A (en) * 1981-03-02 1983-10-04 Bridges Electric, Inc. Fault detector with improved response time for electrical transmission system

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4797805A (en) * 1985-12-20 1989-01-10 Asea Aktiebolag Fault location in a power supply network
US4800509A (en) * 1985-12-20 1989-01-24 Asea Aktiebolag Detection of high resistance faults in electrical power supply network
US4800374A (en) * 1986-10-31 1989-01-24 Cray Research, Inc. Personnel antistatic test device
US4851782A (en) * 1987-01-15 1989-07-25 Jeerings Donald I High impedance fault analyzer in electric power distribution
US4991105A (en) * 1988-12-21 1991-02-05 Accu-Scan, Inc. Microprocessor controlled ground system monitor
DE4011076A1 (de) * 1989-04-05 1990-10-18 Chubu Electric Power Nullstromdetektor
US5159561A (en) * 1989-04-05 1992-10-27 Mitsubishi Denki Kabushiki Kaisha Zero-phase sequence current detector
US5365179A (en) * 1992-03-19 1994-11-15 Electronic Development, Inc. Apparatus and method for measuring ground impedance
DE4413068A1 (de) * 1993-04-15 1994-10-20 Hitachi Ltd Vorrichtung zum Erkennen einer Isolierungsverschlechterung
US5493228A (en) * 1993-09-28 1996-02-20 Asea Brown Boveri Ab Method and device for measuring and recreating the load current in a power network in connection with the occurrence of faults
US5506789A (en) * 1993-10-15 1996-04-09 The Texas A & M University System Load extraction fault detection system
US5790038A (en) * 1994-04-22 1998-08-04 Scasciafratti; Gianfranco System for the remote measuring of the protection ground
US5550476A (en) * 1994-09-29 1996-08-27 Pacific Gas And Electric Company Fault sensor device with radio transceiver
US5973500A (en) * 1996-06-14 1999-10-26 Electricite De France-Service National Apparatus for detecting insulation defects in devices connected into power distribution networks
WO2000062084A1 (en) * 1999-04-12 2000-10-19 Chk Wireless Technologies Australia Pty Limited Apparatus and method for electrical measurements on conductors
WO2004079378A1 (en) * 2003-03-05 2004-09-16 Jan Berggren Detection of earth faults in three phase systems
CN104237731A (zh) * 2014-09-25 2014-12-24 福州大学 基于eemd与能量法的谐振接地配电网单相接地故障选线方法
CN104237731B (zh) * 2014-09-25 2017-01-18 福州大学 基于eemd与能量法的谐振接地配电网单相接地故障选线方法
US9991694B1 (en) 2014-10-27 2018-06-05 Becker Mining America, Inc. Multi-channel tone monitor system and method for ground wire monitoring using same
CN104597378A (zh) * 2015-01-26 2015-05-06 福州大学 基于暂态非工频零序电流的含dg配电网的故障选线方法
CN104597378B (zh) * 2015-01-26 2017-09-15 福州大学 基于暂态非工频零序电流的含dg配电网的故障选线方法
US11522355B2 (en) 2018-05-18 2022-12-06 Abb Schweiz Ag Method and apparatus for use in earth-fault protection
CN111965487A (zh) * 2020-08-12 2020-11-20 国网江苏省电力有限公司盐城供电分公司 一种高压输电线路接地故障检测控制方法
CN111965487B (zh) * 2020-08-12 2022-11-08 国网江苏省电力有限公司盐城供电分公司 一种高压输电线路接地故障检测控制方法

Also Published As

Publication number Publication date
FI823717A0 (fi) 1982-11-01
EP0082103B1 (de) 1986-04-16
EP0082103A1 (de) 1983-06-22
FI74365B (fi) 1987-09-30
DE3270665D1 (en) 1986-05-22
FI74365C (fi) 1988-01-11
CA1191904A (en) 1985-08-13
SE8106436L (sv) 1983-05-03
SE446678B (sv) 1986-09-29
NO823615L (no) 1983-05-03
DK484082A (da) 1983-05-03
NO157758C (no) 1988-05-11
FI823717L (fi) 1983-05-03
NO157758B (no) 1988-02-01

Similar Documents

Publication Publication Date Title
US4529929A (en) Method of detecting ground faults in a network for distribution of electric power and a device for carrying out the method
EP0227017B1 (en) Method for detecting high resistance ground faults on a power transmission line
Eriksson et al. An accurate fault locator with compensation for apparent reactance in the fault resistance resulting from remore-end infeed
US6256592B1 (en) Multi-ended fault location system
US5773980A (en) One-terminal fault location system that corrects for fault resistance effects
CN105388391B (zh) 用于使用分布式通信来识别故障位置的系统和方法
US6466031B1 (en) Systems and methods for locating faults on a transmission line with multiple tapped loads
EP1195874B1 (en) Method for identification of a faulting or faulted sending end or feeder branch in an electrical distribution system
EP3506445A1 (en) System for identification of a feeder with high-ohmic earth fault in a distribution network
GB2070869A (en) Detecting faults on transmission lines
WO1995024014A2 (en) One-terminal data fault location system
EP1971869A1 (en) Method and device for fault location in a two-terminal transmission or distribution power line
GB1603291A (en) Protective relay for an electrical transmission line
GB2373586A (en) Locating a fault on a transmission line with a tapped load
CA2068952A1 (en) Isolation monitoring and measuring device for an electrical power system with isolated neutral
EP1018027B1 (en) Method for the location of a high-resistance earth fault in a power distribution system on the basis of current measurements
US3838314A (en) Detector for reverse and open phase in a three phase circuit
JPH11271384A (ja) 非接地系電路の線路定数計測装置及び地絡監視装置
EP1065510B1 (en) Location of restriking and transient earth faults
US20020080535A1 (en) Multiple ground fault trip function system and method for same
Biller et al. Protection algorithms for closed-ring grids with distributed generation
US20230142049A1 (en) Fault detection in a power transmission system
US3413523A (en) Protective relay for an electrical system
EP0203472B1 (en) Method for obtaining a backup function for a digital distance relay and relay to carry out the method
FI115093B (fi) Suojarelejärjestely sähkönjakeluverkon oikosulku- ja maasulkusuojauksessa

Legal Events

Date Code Title Description
AS Assignment

Owner name: ASEA AKTIEBOLAG VASTERAS,SWEDEN A SWEDISH CORP.

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:BERGGREN, JAN;REEL/FRAME:004097/0392

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 4

LAPS Lapse for failure to pay maintenance fees
FP Lapsed due to failure to pay maintenance fee

Effective date: 19930718

STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362